Improvement in bridges



encuenr P. HERTHEL. Jn.,

@anni dattie-r.,

or sr. Louis, MISSOURI.

Letters `Patent No. 98,8166, dated January 18, 17870.

IMPROVEMENT IN BRIDGES.

The` Schedule referred toin these Letters Patent: and making paxt of thesama To, all whom it may concern:

Beit known that I, Georgen P. Hnnrnnn, Jr., ofthe city of' St. Louis, inthe county of St. Louis, and State of Missourhhave made certain new anduseful Improvements in Bridges; and I do hereby declare that thefollowing is a full and true description thereof, reference being had tothe accompanying drawings, and to the letters of reference markedthereon.

This invention relates more especially to bridge and similar structures,constructed principally of wrought-A iron or steel.

This invention relates, in its nature, first, to the manner ofconstructing the compression-posts or struts l of' a bridge, andconnecting the same with the upper and lower chords.

Said nature is, secondly, in the manner of connecting the posts orstruts of a. bridge-truss with the upper or lower members and thediagonal rods or braces, and herein this invention more particularlyrelates to the manner of placing the parts comprising the upper orcompression-member of a bridge-truss in such posi- Y tion, relative tovertical planes tothe parts comprising Figure 1 as a general elevationof' a bridge-truss yin its usual form, showing such parts as aredeemed'essential to this description.

Figure 2 is an end view. Figure 3 is a sectional elevation, and Figure 4lis a horizontal sect-ion, both of said figures showing the joint ofthestrut or post, with the upper member or cord.

Figure 5 is an elgvation, showing the joint at the lower chord, and thesupport of the door-beam or cross-bearer; r

Figure 6 is a plan of the same, enlarged;

Figure 7 is a-vertical sectional elevation, showing the joint of thepost, with the compression-chord, as used in large bridges; and

Figure 8 is an axial horizontal section of the same.

Figures 9 and l0 show an angle-iron post or, strut, in sectional planand'elevatiou, and

Figures 11 and 12 show a corrugated-iron post or strut, in sectionalplan and elevation. i

The bridge-truss is constructed in any of the forms adapted to properlyreceive the strains and carry the load placed thereon. l

As shown in the figures- A is the compression-member, or top chord.v

l, the tension-member, or lower chord.

C are the posts or struts, actingunder compression principally, butformed to sustain tension also.

D are the braces, acting solely under tension when arranged in the formshown. Y

The upper chord will generally be made of rolled channel-bars, I orT-beams, so as to properly resist thestrains thereon. which I have shownformedof corrugated iron.

Said post has a cap, c, upon which the parts of the upper chord rest,being held laterally by a casting, E, arranged between the chord-barsand above the cap c.

A bolt, F, passes through the chord A and the casting E, securing saidparts.

The cap c (and similarly the cap c1, hereafter referred to,) is fittedwithin and above the corrugated-iron post- .body, so that said ironrests fairly under a projecting angeof the cap, and fits about avertical partforA tenon of the cap. Around the corrugated-iroman annularfillet is then arranged, held on by a band, which will be shrunk orforged on, generally in the manner indicated in figs. 1, 2, 11, and12.

The casting E rests, by its upper flange, on the chord-bars, and hasproper bearings for the braces D. The casting passing over the verticalend edge of the chords, is drawn down on, and also horizontally againstthe upper chord, retaining it on the post, and causing thecompression-strain in the post and chord. Similarly a casting, G, isplaced between the parts of the lower chord, and connects with saidparts by a. bolt, H. The casting G is firmly secured to the kbase c ofthe post O1, thus making a firm connection between the post and lowerchord.

As none of the braces D pass through the body of y the end-post G1, itwas formed, as before stated, of' corrugatediron in an endless cylinder.

The other posts, OZ and O, will usually be arrangedv to pass the bracesbetween their sustaining members, and are formed, in accordance with thenature of this invention, of angle-iron, channelbars, I or l'fbeams, orsimilar parts, which are set apart, as indicated in the drawings.` l iIn small bridges, where the truss-height is msufhcient to allow for toplateral bracing, it is important to support the upper member A againstlate-ral vibration. I therefore employ ajoist of post and top chord, asindicated in figs. 1, 3, and 4; the post G2, passing 'up between the.parts a of the upper member, and a casting, I, being used to space thesaid parts, as well as form the proper bearing for the braces D.

To bind the parts, a joint-bolt, i, passes through the chord andcast-ing I. v u v I prefer arranging a joint of the chord-preces a inthe vertical axis of the post, as at al, the joint being made good bythe usual lap-plate, and this being These rest upon the end-post C',

YC2, the post being either set upon the casting itself,

. (this acting as a saddle,) and said cross-bearer translower chord,then the, rib K will be arranged parallel I arrange castings, N1,fitting to the plate N, and without I arrange a wrought-iron or steelbaud, N2,

the band N2 to draw up in shrinking.

placed between the parts c2 of the post, thus acting to prevent thepostfrom longitudinal movement under strain of the braces. I

The cap of the casting I may fit around or about the outer edges of'the. parts c2, in this wisc, holding the post in all directions.

A casting, K, receives the lower end of the. post or it may pass to thelower edge of the lowcrchord, and the cap k may retain the post. Aproper bolt here again passes `through the lower chord and the castingK, and the lap-plates b act to prevent'longitudinal movement.

In case an increase of metal section is needed in the upper or lowerchord, this `is usually' accomplished by adding a plateto the originalchord. `Said added plate is placed vertically against the part ofthechord, as shown at a, in fig. 4, so that the additional plate abutsfairly against the post C2 C, and receives thereti'om thecompression-strain, (through the action of the brace,) as well asprevents the longitudinal displacement of the post.

To support the floor-beam or crossbearer, and to permit the same to actas a lower lateral strut, I arrange the casting Kwith a vertical rib,K', extending above the lower chord B, and fitting against the innersurfaces of the post angle-irons'.

The cross-bearer L then secures to the casting K,

mitting its pressures as a wind-strut to the rib Kand the post C2.'

Said rib is then also arranged with proper bearingsurfaces to receivethe wind-braces M, as more clearly shown in fig. 6.

It' the crossbearer extends laterally beyond the with the cross-bearer,and bolts will be used to connect the latter with the rib and itssaddle-casting K.

In large bridges, the height of' truss is suflicient to permit lateralbracing between upper chords; and as here it becomes more particularlynecessary to economize in width'ot'ltruss, I arrange the parts c3 of thepost (la under the parts a of the chord A, as indicated in figs. 7 and8.

Here,- again, the connection of post and chords is made by propercastings and through-bolts. Ii', by necessity of increases of strain, agreater number of chordparts is needed, then the additional parts willbe arranged in the same horizontal plane with the part-s before in use,and under each new chord-part, a post-part (similar to c3) may beplaced, in accordance with the nature of this invention.

In very long panels, where the points of' support to the upper chord arefar apart, this chord will be formed in members arranged above each, andspaced and connected, as hereafter described, for the construction ofcompression-members.

To confine the ends of the post, bands will be used', and the chords ofopposite trusses will be connected by lateral bracing generally, asindicated in figs. 7 and 8, or in any other proper manner.

For the purpose of' forming a strong and economical post, where bracesdo not require passage-way, (as-at ends of trnsses,) and especially forforming columns in buildings, telegraph-posts, and similar structures, Iuse corrugated or similar iron (or steel) plate N. This'is formed to acylinder, either circular or polygonal in general outline, as shown iufigs. ll and 12. Within such cylinder, especially at top and bottom,

which will be forged or sin-unir on, and which has a properbearing-ring, N, fitting to the' outer plate-surice of the post. Thering N 3 should be split, to allow Similarly for posts, especially onbridge-trusses where braces pass through the posts, I arrange theangle-iron or-stcel (or other shape) bars O, and with- I in these thespacing-castings O, and secure thc parts hy bands O2, passing around thebars and castmgs.

By uicking the plate N or the bars O, the inner castings and the baudswill be prevented from slipping down under violent jar or vibration.

ln the use of shape iron posts may be formed of a rectangular,hexagonal, or other polygonal outline, and as a form well adapted forbridge-work, I mention the one produced from f1-bars.

It is apparent that a compression-member, (such as a post or strut-,)when formed of several parts to act as awhole, must be firmly secured,so that its several parts shall act conjointly. This, it is plain, isachieved by the castings O1 and band O2, the latter, by great power,binding the several parts, to prevent buckling or even displacementaxially. l

Again, the joint of' the several parts thus made does not cut away theavailable metal section of any Aof the sustaining members, and theseveral sustain-y ing members may be placed at such distances apart asto give the post, strut, or compression-chord the required diameter orareal dimensions to prevent buck-- ling or transverse strains.

By placing angle or channel-iron with the flanges of the several membersof the post at the farthest pos. sible remove from the vertical axis ofthe post,` a form similar to that of' iig. 9 is achieved. This form isof 'rectangular outline, and two of its surfaces being placed parallelto the vertical planes of the longituldinal upper or lower chord-stripsor members, the joint of the post and said chord-strips may be achievedby a metal contact of the several members, which are contiguous, thusavoiding dangerous joint-castings and other than rectangular orso-called square fittings.

Lastly, in using endless sections, `as when applying corrugated iron,inner cast-ings aresnot absolutely required, and, by riveting cylinderto cylinder, great lengths of Vposts may be achieved.

lo attain great lengths without rive-ling, the cylin-v ders (or the barsO) may rest, one above the other, and then castings N1 or Ol may beemployed within and bands without to secure the joint.

Having thus fully described my invention,

What I claim, is,-

1. A post, strut, orA other compression member, formed of' corrugatedmetal. with or without inner castings, aud arranged with caps fitted atends, and secured by bands shrunk or forged on, substantially as' setforth. f

2. Passing the posts or strut-s between the parts of the upper chord,and securing the parts by a joint casting 'and bolts or bands,substantially as set forth.

3. ,lhe arrangement of the lap-plate in joints of the upper or lowerchords, to holdv the post against longitudinal movement, substantiallyas set forth.

v 4. The plate I, receiving the braces D, and arranged between the partsof the upper chords, and also resting thereon and between the postparts, substantially as set forth.

5. The casting K, arranged between the parts of the post and the lowerchords, and receiving the thrust of the wind-strut and strain of' thelateral braces, substantially as set forth.

6. Arranging the part-s of the post or strut .vertically under parts ofthe compression-chord, substain tially as set fort-h.

In testimony whereof, I have hereunto signed my name, in the presenceof- GEO. P. HERTHEL, JR.

Witnesses:

WILLIAM W. HERTHEL, ROBERT Bums.

